All electrical pages are for information only! New rules have been introduced for electrical safety in the home, please read this document by clicking here, before starting any electrical work


Before working on any electrical circuit you must ensure that it is isolated correctly and cannot accidentally be switched back on. Please read the article on safe isolation procedures before doing any electrical work. If you are not 100% certain what you are doing call a qualified electrician. Building regulations are changing all the time and modifying your home electrics could be against new rules and could invalidate your home insurance, if in doubt check first!


Please note that all wiring diagrams are specific to the UK and could be dangerous if applied elsewhere.

It is recommended that you read all the pages on electricity starting with electrical safety.


Appendix D: New harmonised cable identification colours

Amendment No 2 to BS 7671: 2001 published on 31 March 2004 specifies new (harmonised) cable core colours for all new fixed wiring in electrical installations in the UK. It includes guidance for alterations and additions to installations wired in the old cable colours.
Table D1 below gives the new cable core colours for ac power circuits. Figure D1 shows examples of flat and armoured single phase and 3-phase ac power cables with the old and the new harmonised colours.

Table D1: Identification of conductors in ac power and lighting circuits
Conductor Colour
Protective conductor Green-and-yellow
Neutral Blue
Phase of single phase circuit Brown
Phase 1 of 3-phase circuit Brown
Phase 2 of 3-phase circuit Black
Phase 3 of 3-phase circuit Grey
The new (harmonised) colour cables may be used on site from 31 March 2004.


harmonised cable colours

Examples of cables with old and new colours


New installations or alterations to existing installations may use either new or old colours, but not both, from 31 March 2004 until 31 March 2006.

Only the new colours may be used after 31 March 2006.

For single phase installations in domestic premises, the new colours are the same as those for flexible cables to appliances, namely green-and-yellow, blue and brown for the protective, neutral and phase conductors respectively.

Further information, including cable identification colours for extra-low voltage and dc power circuits, is available from the following sources:

New wiring colours. Leaflet published by the IEE, 2004. Available for downloading from the IEE website

ECA comprehensive guide to harmonised cable colours, BS 7671: 2001 Amendment No 2. Electrical Contractors’ Association, March 2004.

New fixed wiring colours - A practical guide. National Inspection Council for Electrical installation Contracting (NICEIC), Spring 2004.

To view the full document please search the internet for the latest approved part p document. We cannot link to the document directly as it keeps changing and is never in the same place for long.

Published with permission from HMSO/ Part P building regulations